So, check the timing, post results, and we'll move onwards...SO, next step is to check the timing.
After that, I would re-ask a question I already asked you which I believe you did not answer. If you look back at my posts in this thread, you'll probably find it. The question was how long was this car sitting apart? The whole reason I asked that question in the first place was specifically because of the lifters being a potential problem. You tell me it sat for a long time, I'll tell you to swap the lifters from one head to the other, in exact positions on the opposite head, and redo your compression test to see if you can move the compression results exactly across from one head to the other. OR, if you want to just get right down to the nitty gritty, remove the head whilst it is fully assembled with the cam in place, and LOOK to see if the valves are open.
However, from my experience with this exact (lifter) problem [and yes, I have some!] - the vehicle had ZERO compression in all holes with bad lifters. However, upon inspection of those lifters, it was duly noted that the valves were held open varying amounts - though in all cases enough that zero compression was the result. And in all cases, the amount was actually very visible. And of course, if you removed the cam and lifters, the valves shut nice and tight. Problem identified. The fact that you actually have some compression tells me they'd barely be open at all. It's not enough information to say they are bad or that your valves are bent. All we know based on your compression results is that the valves are open (at least very slightly) when they should not be.
It is a definite possibility that the lifters could need replacing. (I would replace, not rebuild, but that's me)
In any case, check your timing belt first.
Then you'll have to make some decisions depending on what you find at the belt.
I'd say it depends on what you'd rather do. Would you rather try to work on the Z pulling the plenum and getting down to remove the valve covers, cams and lifters while it's in the car, just to do the moving of lifters across to PROVE it is lifters...or would you rather just pull the motor again, then do the work on an engine stand and REMOVE the head to visibly check it. It might be more of a PITA to do it in the car and move lifters across - and if the lifters are bad - great - but if they're not, then you are back to pulling the motor anyhow. Of course, if you just pull the motor and rip the head off, you will want probably have to replace the head gaskets, and if the lifters are the problem - well - then that step wasn't necessary and you wasted a set of head gaskets. Hahah. So, that's why I say you've got some decisions to make on how to proceed AFTER you check your damn timing belt. And it's also important how long this car sat - because the longer it sat, the more easily I'd be convinced it could be lifters. I didn't ask you how long it was apart because I was curious...Hahah!I have all the necessary experience with the Z to help you with the mechanical, as do many other members on the forum - but it is solely based on your feedback - and it needs to be one or a few steps at a time until the actual problem is identified.
09:15:09 12/17/09
